The present invention relates to a method and apparatus for the mass-production of carrying devices for seeds or plant cuttings, i.e., for incipient plants (hereinafter called carrier devices or incipient plant carrying devices). More particularly, the invention relates to improvements in a method and apparatus for producing substantially cylindrical incipient plant carrying devices of the type wherein a tubular (e.g., cylindrical) envelope or wrapper surrounds a mass of filler material which can contain one or more seeds or plant cuttings.
It is already known to make carrying devices of the above outlined character by assembling filler material and a web of wrapping material into a rod which is thereupon severed to yield a succession of discrete carrying devices. The filler material is intended to provide breeding ground for the germination of seeds and/or for the growing of roots, at least for a certain period of time before the plants can be embedded in soil in the field, in a garden or in a nursery.
U.S. Pat. No. 3,049,576 discloses substantially cylindrical incipient plant carrying devices, and U.S. Pat. No. 3,456,386 discloses a mode of producing such devices. The latter patent discloses the making of filler material in the form of an elongated strip which can consist of continuously produced lignocellulosic material. The strip is thereupon twisted so as to assume a substantially circular cross-sectional outline, and the thus twisted strip is brought into contact with a continuous carrier strip for seeds. The two strips are draped into a web of paper which forms a tubular envelope around the resulting twin-strip filler, and the thus obtained rod is severed at intervals to yield discrete incipient plant carrying devices. Such procedure is cumbersome and expensive in view of the need to form a continuous strip of filler material, to twice such strip, to form a continuous strip of spaced-apart seeds, and to bring the two strips together prior to the making of the actual rod of coherent incipient plant carrying devices.